Abstract:
To compare the effect of different frequency and duration of interval exercise training program on exercise capacity change in patients with chronic heart failure (CHF). Twenty-six CHF parients with NYHA FC II-III were enrolled into the study. They were divided into 2 groups. Group A (M=11, F=2, mean age=59+-7 years, mean LVEF=38+-11%) underwent exercise program 5 times/week x 3 weeks. Group B (M=11, F=2, mean age=57+-9 years, mean LVEF=40+-9%) underwent 3 times/week x 5 weeks. The exercise consisted of 15 min. of interval bicycling (30-s work phases/60-s recovery phases) and 10 min. of interval treadmill walking (60-s work and recovery phases each). A steep ramp test was developed to derived maximal short time exercise capacity (MSEC) for work phases in interval bicycle raining, which used 50% of MSEC for exercise intensity. The peak oxygen consumption (peak VO2) from ordinary ramp test were assessed before and after the training programs. The result showed that MSEC and peak VO2 was significantly increased in both groups: MSEC: group A; from 141.15+-53.74 to 184.77+-65.75 W. (p<0.000), group B; from 157.77+-54.88 to 204.62+-59.18 W. (p<0.000), peak VO2: group A; from 13.32+-3.77 to 15.54+-5.14 ml/kg/min (p<0.018), group B from 14.88+-4.32 to 17.64+-4.10 ml/kg/min (p<0.000). Compared between group A and B, the MSEC (p=0.72) and peak VO2 (p=0.54) changed were not significantly different. Conclusion: The improvement in exercise capscity of CHF patients performed interval training 3 times/week x 5 weeks was not different from the program performed 5 times/week x 3 weeks.
